Question

Va rog, coronita si 50 puncte. Rezolvati prin metoda reducerii sistemului de ecuatii​

Answer 1

$\small\begin{cases}4x - 7y = 30 \\ 4x - 5y = 90\end{cases}\implies \: \begin{cases}4x - 7y = 30 \\ - 4x + 5y = - 90\end{cases} \\ (\text{adunam}) : - 2y = - 60\implies \:\underline{y = 30} \\ \implies \: 4x - 210 = 30\implies \:\underline{ x = 60}$